ixgbe: add support for older QSFP active DA cables

This patch adds support for QSFP active direct attach (DA) cables which
pre-date SFF-8436 v3.6.

Signed-off-by: Emil Tantilov <emil.s.tantilov@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

2 files changed, 50 insertions, 10 deletions

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_phy.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_phy.c
index e89b34eae4db..e4c676006be9 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_phy.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_phy.c
@@ -1175,6 +1175,10 @@ s32 ixgbe_identify_qsfp_module_generic(struct ixgbe_hw *hw)
         u8 comp_codes_10g = 0;
         u8 oui_bytes[3] = {0, 0, 0};
         u16 enforce_sfp = 0;
+        u8 connector = 0;
+        u8 cable_length = 0;
+        u8 device_tech = 0;
+        bool active_cable = false;
 
         if (hw->mac.ops.get_media_type(hw) != ixgbe_media_type_fiber_qsfp) {
                 hw->phy.sfp_type = ixgbe_sfp_type_not_present;
@@ -1217,12 +1221,6 @@ s32 ixgbe_identify_qsfp_module_generic(struct ixgbe_hw *hw)
                         hw->phy.sfp_type = ixgbe_sfp_type_da_cu_core0;
                 else
                         hw->phy.sfp_type = ixgbe_sfp_type_da_cu_core1;
-        } else if (comp_codes_10g & IXGBE_SFF_QSFP_DA_ACTIVE_CABLE) {
-                hw->phy.type = ixgbe_phy_qsfp_active_unknown;
-                if (hw->bus.lan_id == 0)
-                        hw->phy.sfp_type = ixgbe_sfp_type_da_act_lmt_core0;
-                else
-                        hw->phy.sfp_type = ixgbe_sfp_type_da_act_lmt_core1;
         } else if (comp_codes_10g & (IXGBE_SFF_10GBASESR_CAPABLE |
                                      IXGBE_SFF_10GBASELR_CAPABLE)) {
                 if (hw->bus.lan_id == 0)
@@ -1230,10 +1228,47 @@ s32 ixgbe_identify_qsfp_module_generic(struct ixgbe_hw *hw)
                 else
                         hw->phy.sfp_type = ixgbe_sfp_type_srlr_core1;
         } else {
-                /* unsupported module type */
-                hw->phy.type = ixgbe_phy_sfp_unsupported;
-                status = IXGBE_ERR_SFP_NOT_SUPPORTED;
-                goto out;
+                if (comp_codes_10g & IXGBE_SFF_QSFP_DA_ACTIVE_CABLE)
+                        active_cable = true;
+
+                if (!active_cable) {
+                        /* check for active DA cables that pre-date
+                         * SFF-8436 v3.6
+                         */
+                        hw->phy.ops.read_i2c_eeprom(hw,
+                                        IXGBE_SFF_QSFP_CONNECTOR,
+                                        &connector);
+
+                        hw->phy.ops.read_i2c_eeprom(hw,
+                                        IXGBE_SFF_QSFP_CABLE_LENGTH,
+                                        &cable_length);
+
+                        hw->phy.ops.read_i2c_eeprom(hw,
+                                        IXGBE_SFF_QSFP_DEVICE_TECH,
+                                        &device_tech);
+
+                        if ((connector ==
+                                     IXGBE_SFF_QSFP_CONNECTOR_NOT_SEPARABLE) &&
+                            (cable_length > 0) &&
+                            ((device_tech >> 4) ==
+                                     IXGBE_SFF_QSFP_TRANSMITER_850NM_VCSEL))
+                                active_cable = true;
+                }
+
+                if (active_cable) {
+                        hw->phy.type = ixgbe_phy_qsfp_active_unknown;
+                        if (hw->bus.lan_id == 0)
+                                hw->phy.sfp_type =
+                                                ixgbe_sfp_type_da_act_lmt_core0;
+                        else
+                                hw->phy.sfp_type =
+                                                ixgbe_sfp_type_da_act_lmt_core1;
+                } else {
+                        /* unsupported module type */
+                        hw->phy.type = ixgbe_phy_sfp_unsupported;
+                        status = IXGBE_ERR_SFP_NOT_SUPPORTED;
+                        goto out;
+                }
         }
 
         if (hw->phy.sfp_type != stored_sfp_type)
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_phy.h b/drivers/net/ethernet/intel/ixgbe/ixgbe_phy.h
index 138dadd7cf33..24af12e3719e 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_phy.h
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_phy.h
@@ -50,8 +50,11 @@
 #define IXGBE_SFF_QSFP_VENDOR_OUI_BYTE0 0xA5
 #define IXGBE_SFF_QSFP_VENDOR_OUI_BYTE1 0xA6
 #define IXGBE_SFF_QSFP_VENDOR_OUI_BYTE2 0xA7
+#define IXGBE_SFF_QSFP_CONNECTOR        0x82
 #define IXGBE_SFF_QSFP_10GBE_COMP       0x83
 #define IXGBE_SFF_QSFP_1GBE_COMP        0x86
+#define IXGBE_SFF_QSFP_CABLE_LENGTH     0x92
+#define IXGBE_SFF_QSFP_DEVICE_TECH      0x93
 
 /* Bitmasks */
 #define IXGBE_SFF_DA_PASSIVE_CABLE           0x4
@@ -68,6 +71,8 @@
 #define IXGBE_SFF_ADDRESSING_MODE            0x4
 #define IXGBE_SFF_QSFP_DA_ACTIVE_CABLE       0x1
 #define IXGBE_SFF_QSFP_DA_PASSIVE_CABLE      0x8
+#define IXGBE_SFF_QSFP_CONNECTOR_NOT_SEPARABLE  0x23
+#define IXGBE_SFF_QSFP_TRANSMITER_850NM_VCSEL   0x0
 #define IXGBE_I2C_EEPROM_READ_MASK           0x100
 #define IXGBE_I2C_EEPROM_STATUS_MASK         0x3
 #define IXGBE_I2C_EEPROM_STATUS_NO_OPERATION 0x0